The PCB printed circuit glossary is designed to give you definitions to some of the words and phrases you will come across in doing business with MOKO. While not exhaustive, it provides useful information about PCB circuits, circuit board design, and circuit board construction.

When it comes to printed circuit board manufacturing and assembly, MOKO offers the reliability and on-time service customers in the Military/Aerospace/Defense/Medical and Commercial Industries depend on.

AQL – (Acceptance Quality Level) – The maximum number of defectives likely to exist within a population (lot) that can be considered to be contractually tolerable; normally associated with statistically derived sampling plans.

Array – A group of elements or circuits arranged in rows and columns on a base material.

Array Up – Number of individual PCBs in the array configuration.

Array X Dimension – In inches, the most extreme array measurement in the X axis, including any rails or borders.

Array Y Dimension – In inches, the most extreme array measurement in the Y axis, including any rails or borders.

Artwork – An accurately scaled configuration of electronic data used to produce the artwork master or production master.

Artwork Master – The photographic image of the PCB pattern on film used to produce the circuit board, usually on a 1:1 scale.

AS9100 - A standardized quality management system developed for the aviation, aerospace and defense industry suppliers that incorporates ISO-9001:2008 and industry requirements in an effort to provide improved quality and performance. Requires authorized registrar audit.

Aspect Ratio – The ratio of the PCB thickness to the diameter of the smallest hole.

B-Stage – An intermediate stage in the reaction of a thermosetting resin in which the material softens when heated and swells, but does not entirely fuse or dissolve, when it is in contact with certain liquids.

Back Drilling - The process of removing the unused portion "stub" of vias by drilling a larger hole from one or both sides after the plating processes. This is typically required in very high speed applications (10GHz or greater) to minimize the parasitic effects of the via stubs.

Barrel – The cylinder formed by plating the walls of a drilled hole.

Bare Board – An unassembled (unpopulated) printed board. You may also be intereseted in BareBones boards.

Base Material – The insulating material used to form the conductive pattern. It may be rigid or flexible or both. It may be a dielectric or insulated metal sheet.

Base Material Thickness – The thickness of the base material excluding metal foil or material deposited on the surface.

Bed of Nails – A test fixture consisting of a frame and a holder containing a field of spring-loaded pins that make electrical contact with a planar test object.

Blind Via – A via extending only to one surface of a printed board. Does not extend from the top to the bottom layer.

Blister – A localized swelling and/or separation between any of the layers of a laminated base material, or between base material or conductive foil. It is a form of Delamination.

Board House – Board vendor. A manufacturer of printed circuit boards. Learn more about Advanced Circuits and our PCB capabilities.

Board Thickness – The overall thickness of the base material and all conductive material deposited thereon.

Book – A specified number of Prepreg plies which are assembled along with inner-layer cores in preparation for curing in a lamination press.

Bond Strength – The force per unit area required to separate two adjacent layers of a board by a force perpendicular to the board surface.

Bottom SMD Pads - Number of Surface Mount Device Pads on bottom

Bow – The deviation from flatness of a board characterized by a roughly cylindrical or spherical curvature such that, if the product is rectangle, its four corners are in the same plane.

Border Area – The region of a base material that is external to that of the end product being fabricated within it.

Buried Via – A via hole drilled through inner-layers of a multilayer board that does not extend to the surface layers. Learn more about our advanced PCB capabilities.

Burr – A ridge surrounding the hole left on the outside copper surface after drilling.